1. Field of the Invention
The invention relates to a noise reduction in an impact tool such as a hammer and a hammer drill.
2. Description of the Related Art
Japanese Patent Publication No. 2646108 discloses an impact tool which performs a hammering operation on a workpiece such as concrete. When the tool bit is driven and the hammering operation is performed, the tool bit receives a reaction force from the workpiece.
In many cases, the reaction force includes not only axial components but also radial components, such that the tool bit undergoes run-out in a radial direction. Such radial run-out is caused not only in the tool bit but also in an intermediate element such as an impact bolt because the impact bolt is in contact with the tool bit. When the tool bit and the impact bolt undergo radial run-out and hit a tool holder for holding them, a metal-against-metal sound caused by such hitting generate noise to the outside via the tool holder and the barrel connected to the tool holder.